东营凹陷古近系泥页岩储层微观结构特征研究

Paleogene Shale Reservoirs Microstructure Characteristics of Dongying Sag

以济阳坳陷东营凹陷沙河街组三段-四段为研究对象,对重点取心井进行厘米级岩心观察描述。结合薄片鉴定、X射线衍射分析、扫描电镜观察、激光共聚焦分析、地球化学测试等方法明确了东营凹陷古近系泥页岩矿物组成、岩石类型、有机地球化学等基本特征。对古近系泥页岩进行岩相类型划分;对储层微观结构特征进行分析。结果表明:1研究区泥页岩岩相划分为4个大类,11个亚类;2研究层段主要发育贫有机质块状混合细粒沉积岩、中有机质纹层状灰岩、中有机质纹层状混合细粒沉积岩、富有机质夹层状灰岩、富有机质页岩黏土岩、层状细粉砂岩和层状白云岩7类岩相;3综合孔隙、裂缝发育程度和储集空间连通性等特征,认为富有机质的夹层状灰岩及富有机质页状黏土岩为最有利岩相类型。

The 3rd and 4th members of Shahejie Formation in Dongying Sag of Jiyang Depression is studied by using detailed despription of core,thin sections identification,analysis of whole rock X-ray diffraction,scanning electron microscopy technologies,confocal analysis. Earth chemical testing methods clearly the basic characteristics of Paleogene in Dongying shale mineral composition,rock type,organic geochemistry,sets up a lithofacies classification scheme,the microstructure of reservoir characteristics are analyzed. The results show that： 1 mud shale phase study area is divided into four categories,11 subcategories. 2 The most developed seven types of lithofacies include organic-lean massive mixed sedmentary rocks,organic-contained laminated limestone,organic-contained finegrained mixed sedmentary rocks, organic-rich calcareous inter-bedded limestone, organic-rich laminated clay stone,Layered fine sandstone,Layered Dolomite. 3 Based on comprehensive porosity,fracture development and reservoir space connectivity,organic-rich laminated clay stone and organic-rich calcareous inter-bedded limestone as advantaged lithofacies in this area.